Console System.CommandLine command one liner with options?

Question

I have a .net console app where I'm trying to make the code more concise. Currently to setup a command using System.CommandLine I have something like this:

using System.CommandLine;

var rootCommand = new RootCommand("CLI");

var theOption = new Option<int?>("--id", "Database ID");

var theCommand = new Command("stuff", "Do Stuff.") { theOption };

ret.SetHandler((id) =>
{
   Console.WriteLine($"Do stuff on id: {id}");
}, theOption);

rootCommand.Add(theCommand);

return rootCommand.Invoke(args);

What I'd like to do is make a one liner, but I'm not sure how to do so since I'm using the variable theOption twice. How could I do this? Looking for something like:

using System.CommandLine;

var rootCommand = new RootCommand("CLI");

//refactor theOption into below statement
var theOption = new Option<int?>("--id", "Database ID");

rootCommand.Add(
   new Command("stuff", "Do Stuff.") { theOption }
).SetHandler((id) =>
{
   Console.WriteLine($"Do stuff on id: {id}");
}, theOption);

return rootCommand.Invoke(args);

Any recommendations would be appreciated. My OCD is acting up without the indentation.

score 0 · Accepted Answer · answered Sep 22 '22 at 05:51

Without any knowledge of System.CommandLine, wouldn't you be able to achieve this with a simple extension method?

public static RootCommand Add(this RootCommand root, Command command)
{
    root.AddCommand(command);

    return root;
}

Something like this maybe? and of course whichever other extensibility you want to add, if you wanna make something neat for combining the command and handler, maybe something like this:

public static RootCommand Configure(
    this RootCommand root, 
    Action<int?> handlerAction,
    Option<int?> handlerOption, 
    params Command[] commands)
{
    root.SetHandler(handlerAction, handlerOption);

    for (int i = 0; i < commands.Length; i++)
    {
        root.AddCommand(commands[i]);
    }

    return root;
}

That should shorten it to:

rootCommand.Configure((id) => { Console.WriteLine($"Do stuff on id: {id}"); }, theOption, theCommand, theCommand2);

With however many commands you want, you can also reuse the options for all the commands within the extension method or whatnot, the world is your oyster and all that.

Console System.CommandLine command one liner with options?

1 Answers1